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Teacher | Posted | Education

What is diode?


youtuber, blogger | Posted

  •  Diode is a semiconductor with two terminals that exclusively conducts electrical current in one direction. A PN junction, a basic semiconductor structure with this feature, is required for this to be achieved. It functions like an electricity one-way roadway.

    What is a diode and how it works?
    A semiconductor diode is an electronic component that can only pass current when it is directly driven. As a result, a gray stripe on its body denotes its driving direction, and current must flow from the black side to the gray stripe. As a result, the power supply's negative terminal must be connected to the diode's gray stripe in order for it to be directly polarized.
    When the diode is reverse biased, however, it acts as an obstructive to current flow. As a result, it can be employed to protect electronic circuits from reverse currents. Other features were discovered over time, and they began to build special inversely polarized diodes, known as Zener diodes. When revering, these act as voltage regulators, managing the voltage in a circuit.

    The PN junction
    The diode is built of silicon or germanium and has a junction with two sections that are doped differently. As a result, the features of each of these two zones will be slightly different.
    The P region, which has holes that might be filled with electrons, is the first of these. On the other hand, there is the N region, which has a large number of electrons but cannot cross over to the P zone.
    As a result, there is a zone dubbed the "Depletion Region" in the center of these two regions, which acts as a kind of neutral zone between them.
    The electrons are able to cross the depletion area when this PN junction is directly biased, that is, when the positive terminal of a voltage source is linked to the P junction and the negative terminal is linked to the N junction. As a result, current flows through the PN junction when it is directly biased.
    When electrons are reverse polarized, they are unable to penetrate the depletion area, preventing electrical current from passing through the PN junction.

    Because diodes are the most frequent in electronic circuits, we separated four of them to display their symbologies. The common diode, for example, conducts exclusively when forward-biased and inhibits current flow when reverse-biased.
    The second is a light-emitting diode (LED), which generates light when it is directly polarized. The photodiode, which generates a voltage at its terminals when exposed to light, is the third component, while the Zener diode, when reverse-biased, acts as a voltage regulator.

    Diode Operation in Circuits
    The diode exclusively transmits electrical current in one direction, as if it were a one-way street. Current flows normally when it is polarized in the proper direction, that is, properly polarized, albeit with a slight voltage drop. It's between 0.6 and 0.8 volts. An example of a forward-biased diode is as follows:
    When we try to polarize it in the opposite direction, it opposes current flow, as if it were an open circuit. As a result, the component can be used in a variety of circuits where only one direction of current is desired, such as rectifier circuits. The issue is that if the voltage surpasses the reverse voltage limit that the component can withstand, it will short-circuit and collapse. The reverse voltage varies depending on the component used in the manufacturing process.

    When a diode is reverse-biased, all of the voltage from the source is applied across it, and no current flows through it. It's worth noting that the diode isn't immediate; it takes some time for it to start conducting current when it's directly biased. Because this can be harmful to high-frequency circuits, higher-frequency components have been developed. Low frequency diodes, such as those used in bridge rectifiers, are ideal for low frequencies.

    Diode Drop Voltage
    When a diode is forward biased, a voltage drop will occur. When applying a voltage below its drop voltage, it will not conduct. The diode only starts to conduct when the voltage is greater than the drop voltage V0 of the component.
    Also, when the component is inversely polarized, that is, when the voltage is negative, it does not conduct until it hits its limit, which is labeled "Disruption" on the graph, when it shorts and begins to conduct all of the current.

    Do two diodes in parallel support more reverse voltage?
    Many people assume that putting two diodes in series boosts their ability to withstand reverse voltage. The answer is no; what will happen is that one of the two diodes will fail first, and the current will be carried by that diode, which will short-circuit.

    Zener Diode
    It's also known as a voltage regulator diode, and it's extremely similar to a regular one except that it's reverse-biased. Building a circuit for a power supply with a maximum output voltage of 6 volts is an example. For this, a special Zener diode is set to run at 6 volts inversely polarized, and it conducts and absorbs current when the voltage exceeds 6 volts. It will regulate the power supply output voltage in this manner.
    See what we term an excess voltage protection circuit with a Zener in the diagram below:

    When the Zener is directly polarized, it operates like a regular diode, with a voltage drop across the junction. As a result, the component is highly useful in applications where the voltage of some output needs to be regulated.

    LED - Light Emitting Diode
    The LED is the most well-known type of diode, and its primary function is to emit light. LEDs are frequently utilized to transfer light data from a circuit in a straightforward manner. It has the advantage of being simple to use in an electrical circuit. The LED generates a monochromatic light, the color of which is determined by the manufacturer. LEDs have the advantage of being inexpensive, high-performing, and long-lasting.

    Diode Applications
    There are millions of uses for this component, but here are a few of the most well-known:

    • Rectifier bridges
    • Avoid reverse currents that can damage components
    • Led lightning
    • Voltage regulators (zener diodes)
    • Diode photos


| Posted

A diode is a two-terminal electronic component that conducts current primarily in one direction; it has low resistance in one direction, and high resistance in the other.


Content writer | Posted

Diode is an electrical  device that allows the flow of current in only one direction. In circuit diagrams, a diode is shown as a triangle with a line across one vertex.It  acts as a one-way switch for current. It allows current to flow easily in one direction, but stops current from flowing in the opposite direction.Diodes are rated according to their type, voltage, and current capacity.  If the current  capacity of diode is exceeded and the diode fails, it may short and two things can happen, either it allow current to flow in both directions or stop current from flowing in  both the  direction.



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